Grease gun piston and reservoir latch



1933- l. L. EASTMAN 1,924,841

GREASE GUN PISTON AND RESERVOIR LATCH Filed March 2, 1933 3 Sheets-Sheet1 Aug. 29, 1933. LLEASTMAN 1,924,841

GREASE GUN PISTON AND RESERVOIR LATCH Filed March 2, 1933 3 Sheets-Sheet2 Zfokiggs Aug. 29, 1933. i I. L. EASTMAN GREASE GUN PISTON ANDRESERVOIR LATCH Filed March 2, 1933 3 Sheets-Sheet 3 fl mm Jive/7&2Jim/.7 Z yam??? Patented Aug. 29, 1933 UNITED STATES 1,924,841 GREASEGUN r-IsToN AND RESERVOIR LATCH H Ivan L. Eastman, Bryan, Ohio, assignorto The Arc Equipment Corporation, Bryan, Ohio, a

corporation of Ohio Application March 2, 1933. Serial No. 659,363 22Claims. (01.221413) The object of my invention is to provide grease gunpiston and reservoir latches which are sirnple, durable andcomparatively inexpensive to manufacture.

' More particularly, it is my object to provide a grease gun reservoirconstruction having therein a follower piston which is spring, extendedand to provide a novel form of piston latch for latch ing the piston inretracted position during the 0 filling operation of the reservoir.

, Still a further object is .to provide the piston latch releasable by alatch actuator which is rotatable and which is in the form of a sleevesurrounding a retracting rod for the follower piston, the sleeve havinga portion exterior of the grease gun reservoir for engagement by theoperator to release the piston latch upon turning the sleeve. Stillanother object is to provide a pistonlatch to an eccentric latchingposition and to provide a latch actuator engageable with the latchwasher to move it toward concentric unlatching position. a p ,v 7 Stilla further object is to provide a latch actuator in the form of arotatable sleeve having an eccentric projection which, in one position,permits the latch washer to assume its eccentric latching position,while inthe opposite position of the latch actuator'the eccentricprojection thereon engages the latchvwasher and moves it tow theconcentric unlatching position.

Still a further. object .islto provide a reservoir latchfor retainingthe reservoir in position on the discharge head of the gun. Anotherobject is to provide the reservoir latch operable by rotating aretracting rod for the grease follower piston whereby the rod servesbothas a retracting rod and as a reservoir latching rod to retain thereservoir in position and eliminate the usual screw-threaded connectionbetween a reservoir and a discharge head.

Still another object is to provide the-reservoir latch in the formof aspider adaptedto against a gasket interposed between the reservoir andthe discharge head when the retract-.

ing rod is rotated, locking means being provided in the form of a latchwasher which is biased coact with lugs on the discharge head, the lugsbeing tapered so as to draw the reservoir tightly to retain theretracting rod in reservoir latchin hand of the operator, atrigger beinglocated substantially midway between the ends of the handle andoperable, to control theadmission of compressed air to the power unitfor dispensing grease from the reservoir and the location of the triggerwith respect to the handle facilitating operation of the gun either inthe ordinary position or in a reversed or up-side-down position. Still afurther object is to provide a control valve which is closed by theincoming air pressure, thus eliminating the necessity for a spring toretain it closed. I

With-these and other objects in view, my invention consists in theconstruction, arrangement and combination of the various parts of mydevice; whereby the objects contemplated are attained, as hereinaftermore fully set forth, pointedout in my claims and illustrated in theaccompanying drawings, in which:

Figure 1 is a sectional view through a reservoir construction showing mypiston latch applied thereto, with the parts in unlatched position.

Figure 2 is an enlarged sectional view of the same, showing the parts inlatched position.

,Figure 3 is a sectional view of a portion of Figure 2 showing thepiston latch about to be operated to latching position. v

Figure 4 is a sectional view, on the line 4-4 of Figure l. a

Figure 5 is asirnilar sectional view on the line 5 5 of Figure 2. r IFigure 6 is a sectional view on the line 6-6 of v Figure2.

Figure 7 is a sectional view through the lower end of the reservoirshowing the discharge head applied thereto. 7

Figure 8 is a sectional view on the line 88 oiFigure 7 showing a planview of the reservoir latch with the reservoir itself and the retractingrod in section. c

Figure 9 is alayout sectional view on the line 9-9 of Figure 8 showingthe coacting retracting rod and'rese'rvoir latch lugs and alsoillustrating their operation for latching the reservoir in position onthe discharge head.v v V Figure 10 is a side elevation. of a grease gunstructure having a trigger of novel construction;

and I Figure 11 is an enlarged view of a portion of Figure 10 showingthe parts in section and illustrating the trigger and valve mechanism.

On the accompanying drawings the reference numeral 10 indicates a greasereservoir of cylindrical formation. It is provided with a head 12 on oneend. A dischargehead 13 is provided on the opposite end thereof. Thedischarge head may be of nozzle, booster or any other type usable inconnection with grease reservoirs.

Within the cylinder 10, I provide a grease follower piston 14. Forretracting the piston 14 I provide a retracting rod 16. It extendsslidably through a packing 18 of thepiston 14 and terminates in a handle26. The rod 16-also extends slidably through a latch actuator 22, whichin turn is rotatable in the head 12. The rod 16 has a head 26 adaptedfor engagement with the piston 14 during the retracting operation asshown in Figure 2.

A spring 28 is located within the cylinder 10 between the head 12 andthepiston 14. adapted to extend the piston for expelling grease in frontthereof into the discharge head or the booster pump usually provided onthe lower end of the cylinder.

During the refilling operation of the'grease reservoir 10 it isdesirable to latch the piston 14 in its retracted position as shown inFigure 2. For this purpose, I provide a sleeve 30 operatively connectedwith the piston 14 and having a tapered nose 32 and a latch groove 34adjacent the upper end thereof. A latch washer 36 is adapted to coactwith the latch groove 34.

The latch washer is retained between a Washer 37 adjacent the head 12and a retainer washer S8. The retainer washer 38 has a slot 39 forguiding the latch washer 36 so that it moves in a straight line whenactuated between concentric and eccentric positions, as shown in Figures4 and 5. The retainer washer 38 is held on the head 12 by screws 41which also prevent rotation thereof relative to the head.

A spring 40 constrains the latch washer 36 to the eccentric position ofFigure 5, although permitting it to move to the concentric position of,.Figure 4 when pressure is applied to cause such movement. One of thescrews 41 engages a depression 43 in the spring 40 to prevent undesiredrotation thereof relative to the retainer washer 38.

The latch'w'asher 36 has a bore 42 with which an eccentric projection23'of the latch actuator sleeve 22 is adapted to coact, as in Figure 1.A knurled head 21 is provided on the latch actuator sleeve 22 for thepurpose of rotating the sleeve to this position for thereby causing suchcoaction.

The latch actuator sleeve 22 is retained in position by a ring 25 sprunginto a groove thereof, thus preventing longitudinal movement of thesleeve outward relative to the head 12.

A head 26 on the retracting rod .16 is formed with a spider orprojecting arms 44 serving to latch the reservoir 10 to the dischargehead 13. For coaction with each arm 44, I provide a latch llug 46, theshape of which is best shown in Figure 9. It will be noted that thelower surface of the lug 46, indicated at 46a. is slightly tapered.Therefore, upon rotation of the arm 44 in the direction of the arrow a,the rod 16 will be drawn toward the head 13, drawing with it the upperhead 12 and the reservoir cylinder 10. This will compress a gasket 48located between the cylinder 10 and the discharge head 13 so as to sealone relative to the other.

After a predetermined degree of compression of the gasket 48", one ofthe arms 44 will havepassed a spring pawl 50 which serves the purpose ofpreventing accidental rotation in a reservoir unlatching direction ofthe handle 20 after it has been rotated to the reservoir latchingposition.

- and 9.

Ibis

Upon sufficient unlatching rotation being imparted thereto by theoperator however, the force of the spring pawl 50 can be overcome whenit is desired to unlatch the reservoir.

Practical operation 'arms 44 to move in the direction of the arrow 22 tothe dotted line. positions shown in Figures 8 The reservoir 10 can thenbe remove from the discharge head 13.

' The latchactuator 22 is then adjusted to the position shown-in Figures2 and 5, whereupon the spring 40 moves the latch washer 38 to itseccentric position. It is now capable of moving back to aconcentricposition, however, against the force of the spring 40. Since theinterior radius of the sectioned hub of the latch 36 (see Figure 4) isthe same as the exterior radius of the eccentric extension 23, theconcentric position mentioned in the last sentence can be attained. Asthe piston 14. is drawn upwardly as shown in Figure 3, the tapered nose32 will engage a tapered bore 36a of the latch washer and force it toconcentric position until the bore 36a registers with the latch groove34. The spring will then cause the washer to snap into the groove. Afterthe refilling operation, the reservoir 10 can be replaced on thedischarge head'l3 with the arms 44 assuming the dotted line positionsshown in Figures 8 and 9. The handle 20 can then be rotated clockwise tothe full line position for latching the reservoir on the head; Torelease the piston 14 and allow the spring 28 to extend it, the sleeve22 is engaged and rotated to the position of Figures 1 and 4, thuscausing the latch washer to assume its concentric unlatching position torelease the piston and permit the spring 28 to force it downwardly fortending to force the grease into the discharge head 13.

In FigurelO, I have shown the reservoir 10 mounted on a power unit A.The power unit is of novel construction having a handle 52 which be'substantially the same in the hand of the J. v.

operator.

A trigger element 54 is mounted substantially midway between the endsofthe handle so that it can be conveniently depressed. regardless ofwhether the handle is in the position shower in a reversed position. Thetrigger itself can be depressed at either end, it being arranged toextend through an elongated opening 56 in the handle 52 and havingshouldered ends58 retained.

against the inner wall of the handle by a spring 60. The central part ofthe trigger element 54 has a projection 62 adapted to engage and swing apivoted bell crank lever 64 for separating a valve'plug 66 from its seat68. It will be obvious that either end of the trigger element 54 can bedepressed or the entire element can be depressed to effect opening ofthe control valve 66. v

The spring 60 holds both the trigger element 54' and the bell cranklever 64 in a predetermined position, the spring itself being supportedby a pin 70 and a retainer member 72.

An air connection is provided for the power unit A and is indicated at74. It communicates with an intake passageway 76. The pressure of theincoming air tends to keep'the valve plug 66 seated so that no spring isnecessary for this purpose. When it is unseated, air passes fromthepassageway '76 into a passageway -'78 from which it flows to theoperating mechanismof the power unit A.

Some changes may be made in the construction and arrangement of theparts of my device without departing from the real spirit and purpose ofmy invention, and it is my intention to cover by my claims any modifiedforms of structure or use of mechanical equivalents, which may bereasonably included within their scope I claim as my invention:- l

1. In a grease gun reservoir construction, spring extended piston, aretracting rod therefor, a latch for coaction with said piston to latchit in retracted position, a rotatable sleeve surrounding said rod, saidsleeve having a hand engaging portion located exteriorly of thereservoir and means engageable by said sleeve to release said latch whenan operators hand engages said portion and thereby rotates said sleeve.

2. In a grease gun reservoir construction, a spring extended piston, aretracting rod therefor, a latch for coaction with said piston to latchit in retracted position and means surrounding said rod and rotatablerelative to said latch to release said latch upon rotation ofsaid'means.

3. In a grease gun reservoir construction, a spring extended followerpiston, a retracting rod therefor, a latch for coaction with saidpiston'to latch it in retracted position, said latch being movablelaterally relative to said retracting rod and a separate means operableupon rotation to impart lateral unlatching movement to said latch.

4. In a grease gun reservoir construction, a spring extended-followerpiston, a retracting rod therefor, a latch for coaction with said pistonto latch itin retracted position, said latch being movable laterallyrelative to said retracting rod and eccentric means rotatable about saidrod and operable upon rotation to impart lateral unlatching movement tosaid latch.

5. In a grease gun reservoir construction, a spring extended followerpiston, a retracting rod therefor, a latch for coaction with said pistonto latch it in retracted position, said latch being movable laterallyrelative to said retracting rod, a latch actuator rotatably movablerelative to said latch and having an eccentric cam surface engageablewith said latch to impart lateral unlatching movement to it.

6. In a grease gun reservoir construction, a spring extended followerpiston, a retracting rod therefor, a latch for coaction with said pistonto latch it in retracted position, said latch being movable laterallyrelative to said retracting rod, a latch actuator rotatably movablerelative to said latch and having a cam surface engageable with saidlatch to impart lateral unlatching movement to it.

'7. In a grease gun reservoir construction, a spring extended piston, aretracting rod therefor,

a latch washer normally biased to an eccentric latching position, saidlatch washer coacting with said piston to latch it in retracted positionand means operable upon rotation thereof to release said latch washer.

8. In a grease gun reservoir construction, a spring extended piston, aretracting rod therefor, a latch washer normally biased to an eccentriclatching position, said latch washer coacting with said piston to latchit in retracted position and means surrounding said rod operable uponrotative movement relative to said latch washer to release it.

9. Ina grease gun reservoir construction, a spring extended followerpiston,a retracting rod therefor, a latch washer for coaction with'saidpiston when said latch washer is in an eccentric position relative tosaid reservoir to latch said piston in retracted position, said latchwasher being movable laterally relative to said retract:

rod, a latch actuator movable rotatably relative to 7 'said latch washerand having a cam surface engageable with said latch washer to impartlateral unlatching movement to it. r 1, 11. In a grease gun reservoirconstruction, a spring extended follower piston, a retracting rodtherefor, a latch washer for coaction with said piston when said latchwasher is in an eccentric position relative to said reservoir to latchsaid piston in retracted position, said latch washer being movablelaterally relative to said retracting rod, a latch actuatorsurroundingsaid rod and movable rotatably relative to said latch washerand having a cam surface engageable with said. latch washer to impartlateral unlatching movement to it. r

12. In a grease gun reservoir construction, a spring extendedfollowerpiston, a retracting rod therefor, a latch washer for coactionwith said piston when said latch washer is in an eccentric positionrelative to'said reservoir to latch said piston in retracted position,said-latch washer being movable laterally relative to said retractingrod,- a latch actuator surrounding said rod and having an eccentricprojection engageable with said latch washer, to impart-lateral;unlatching movement to it upon rotation of said latch actuator.

13. In a grease gun reservoir construction, a spring extended piston, aretracting rod therefor, a latch washer normally biased to an eccentriclatching position, said latch washer coacting with said piston to latchit in retracted position, a guide element limiting said latch washer tomovement in substantially a straight line and means operable uponrotation to move said latch washer relative to said guide element tothereby release said latch washer.

14. In a grease gun reservoir construction, a reservoir cylinder havinga discharge head on one end thereof and means for retaining saidreservoir cylinder on said discharge head comprising a rod extendinglongitudinally through said reservoir cylinder and means for quicklyeffecting connection and disconnection of said reservoir cylinderrelative to said discharge head, said means comprising a plurality ofcircumferentially spaced lugs extending from said rod and a plurality ofcircumferentially spaced lugs on said discharge head for engagementtherewith upon rotation of said rod relative to said discharge head, theengaging surfaces of at least one of said plurality of lugs beinginclined for drawing said reservoir cylinder toward said discharge head.7

15. In a grease gun reservoir construction, a

reservoir cylinder having a discharge head on one end thereof, means forretaining said reservoir cylinder on said discharge head comprising arod extending longitudinally through said reservoir cylinderand havingreservoir latch means thereon to retainingly coact with said head uponrotation of said rod in one direction and to cause nonc'oactionuponrotation of the rod in an opposite direction and stop means to preventaccidental rotation in such opposite direction;

16, In an air operated grease gun construction, a handle for supportinga grease gun, a depressible trigger located substantially midway betweenthe ends of said handle and a control valve for admitting compressed airto the operating mechanism of said gun, said control valve beingnorinally seated by air pressure from the intake of said gun andoperably connected with said trigger to be opened thereby when thetrigger is depressed.

17'. 111 an air operated grease gun construction, ah'aiidle 'forsupporting a grease gun, 'a trigger located substantially midway betweenthe ends of said handle and comprising a trigger element,

said handle having an opening for said trigger element to projectthrough, said trigger element having shouldered ends, means forconstraining said shouldered ends against said handle adjacent the endsof said opening and a control valve for admi'tting'co'mpr'essed air tothe operating mechaiilsm of said gun and operably engaged by the centralpart of said trigger element to be opened thereby when the triggerelement is depressed.

18. In a grease gun reservoir construction, a reservoir cylinder havinga discharge head on one end thereof, means for retaining said reservoircylinder on said discharge head comprismg a rod extending longitudinallythrough said reservoir cylinder and lug means on said rod and on saidhead for coaction with or disconnectio'n from each other and springactuated stop means to prevent accidental disconnection 'of said lugmeans from each other.

19. In an air operated grease gun construction, a handle for supportinga grease gun, a depressible trigger located substantially midway betweenthe ends of said handle and a control 'valve for admitting compressedair to the operating mechanism of said gun, said control valve beingoperably connected with said trigger to be opened thereby when thetrigger is depressed.

20. In an air operated grease gun construction, a handle for supportinga grease gun, a'trigger in said handle and comprising a trigger element,'said handle having an opening for said trigger element to projectthrough, said trigger element having shouldered ends, means forconstraining said shouldered ends against said handle adjacent the endsof said opening and a control valve for admitting compressed air to theoperating mechanism of said gun and operably engaged by the central partof said trigger element to be opened thereby when the trigger element isdepressed.

21. In an air operated grease gun construction,

a handle'for supporting a grease gun, a trigger in said handle andcomprising a trigger element, said handle having an opening for saidtrigger element to project through, said trigger element havingshouldered ends, a control'valve for ad niitting compressed air to theoperating mocha nism of saidgun and operably engaged by the central partof said trigger element to be opened thereby when the trigger element isdepressed and means acting upon the central part of said trigger elementto constrain said shouldered ends against said handle adjacent the endsof said opening.

22. In an air operated grease gun construction, the combination ofagrease gun unit with a reservoir, said unit having a handle for supporting both the unit and the reservoir, air actuated mechanism forreceiving grease from said reservoir and expelling it from said unit anda trigger for controlling the operation or said air actuated mechanismand quickly operable connecting means for connecting said reservoir withand disconnecting it from said grease gun unit by rotation of theconnecting means" through less than a full turn of rotation.

IVAN L. EASTMAN.

